On 04/09/2018 12:12 PM, Michel Dänzer wrote:
On 2018-04-06 08:56 PM, Mario Kleiner wrote:
On 04/06/2018 06:41 PM, Michel Dänzer wrote:
On 2018-04-06 06:18 PM, Mario Kleiner wrote:
On Fri, Apr 6, 2018 at 12:01 PM, Michel Dänzer <mic...@daenzer.net>
wrote:
On 2018-03-27 07:53 PM, Daniel Stone wrote:
On 12 March 2018 at 20:45, Mario Kleiner
<mario.kleiner...@gmail.com> wrote:
We need to distinguish if a backing pixmap of a window is
XRGB2101010 or XBGR2101010, as different gpu hw supports
different formats. NVidia hw prefers XBGR, whereas AMD and
Intel are happy with XRGB.
We use the red channel mask of the visual to distinguish at
depth 30, but because we can't easily get the associated
visual of a Pixmap, we use the visual of the x-screens root
window instead as a proxy.
This fixes desktop composition of color depth 30 windows
when the X11 compositor uses EGL.
I have no reason to doubt your testing, so this patch is:
Acked-by: Daniel Stone <dani...@collabora.com>
But it does rather fill me with trepidation, given that X11 Pixmaps
are supposed to be a dumb 'bag of bits', doing nothing else than
providing the same number and size of channels to the actual client
data for the Visual associated with the Window.
As far as X11 is concerned, the number of channels and their sizes
don't
even matter; a pixmap is simply a container for an unsigned integer
of n
bits (where n is the pixmap depth) per pixel, with no inherent meaning
attached to those values.
That said, I'm not sure this is true for EGL as well. But even if it
isn't, there would have to be another mechanism to determine the
format,
e.g. a config associated with the EGL pixmap. The pixmap doesn't even
necessarily have the same depth as the root window, so using the
latter's visual doesn't make much sense.
Hi Michel. I thought with this patch i was implementing what you
proposed earlier as a heuristic on how to get around the "pixmaps
don't have an inherent format, only a depth" problem?
Do you have a pointer to that discussion?
Ok, apologies, i think i was just taking your comment too far as an
inspiration. The best i can find in my inbox atm. is this message of
yours from 24th November 2017 10:44 AM in a mesa-dev thread "Re:
[Mesa-dev] 10-bit Mesa/Gallium support":
"Apologies for the badly formatted followup before, let's try that again:
On 2017-11-23 07:31 PM, Mario Kleiner wrote:
3. In principle the clean solution for nouveau would be to upgrade the
ddx to drmAddFB2 ioctl, and use xbgr2101010 scanout to support
everything back to nv50+, but everything we have in X or Wayland is
meant for xrgb2101010 not xbgr2101010. And we run into ambiguities of
what, e.g., a depth 30 pixmap means in some extensions like
glx_texture_form_pixmap.
A pixmap itself never has a format per se, it's just a container for an
n-bit integer value per pixel (where n is the pixmap depth). A
compositor using GLX_EXT_texture_from_pixmap has to determine the format
from the corresponding window's visual.
"
There's nothing in there that suggests my root window solution.
I guess i thought given that we can not get the visual of the window
corresponding to the pixmap, let's find some window which is a good enough
proxy for onscreen windows with associated depth 30 pixmaps on the same
x-screen.
A pixmap isn't necessarily associated with any window.
My (possibly inaccurate) understanding is that one can only create a
depth 30 pixmap if the x-screen runs at depth >= 30. It only exposes
depth 30 as supported pixmap format (xdpyinfo) if xorg.conf
DefaultDepth 30 is selected, whereas other depths like
1,4,8,15,16,24,32 are always supported at default depth 24.
That sounds like an X server issue. Just like 32, there's no fundamental
reason a pixmap couldn't have depth 30 despite the screen depth being lower.
Out of curiosity, can you share the output of xdpyinfo with nouveau at
depth 30?
[...]
At least i don't remember seeing any "depth 30, ..." line ever on any
driver+gpu combo if i run X at default depth 24?
I'm not questioning that's currently the case, I'm saying there's no
particular reason for it, so expect it to change at some point.
Ah ok, thanks for the explanation.
I'm interested in the full xdpyinfo *at screen depth 30*, in particular
whether it lists only one variant of depth 30 visuals. If so, one
possibility for a kludge would be to just look at any depth 30 visual.
Ok, the fresh v2 patch implements that kludge. This one retested to work
on nouveau, ati, intel.
On intel and nouveau we only get one channel mask for depth 30 visuals
in xdpyinfo. On amd we get both masks for xrgb2101010 and xbgr2101010,
as the amd gallium drivers expose both formats, but the ordering is
xrgb2101010 first, so that's fine when picking the first depth 30 visual
to get the channel mask for decisions.
The basic problem with EGL based compositing is that for eglCreateImageKHR()
all we have is the EGLDisplay and EGLContext used for importing an image
resource.
Is there no EGLConfig associated somehow?
I guess we could get the EGLConfig from the context, but i assume this
context of the importing application (e.g., typically x11 compositor)
could have an EGLConfig possibly unrelated to depth 30 pixmaps.
P.S. IME nouveau is in for a world of pain in general with a format
which doesn't start at bit 0. Once upon a time, I explored this approach
for depth 24 on big-endian hosts, but ran into lots of issues both in
xserver and on the client side.
Can you clarify for me what you mean with "doesn't start at bit 0"? The
position of red and blue channel is swapped in nouveau's depth 30
format, but the red channel fills the 10 LSBs. So if there are padding
bits, they are the 2 MSBs.
thanks,
-mario
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/mesa-dev
